Field of the Invention
The invention relates to the preparation of drinks or likewise, from an extraction material, such as ground coffee, which is contained in a capsule. The invention further relates to a brewing method as well as to a preparation system for a brewed product.
Description of Related Art
Extraction apparatus for preparing drinks from an extraction material present in a portion package are known, for example, as coffee machines or espresso machines and, as was hitherto the case, are enjoying increasing popularity. In many corresponding systems, the portion packages are designed as capsules, in which the extraction material is closed off, for example, in an airtight manner. The capsule is pierced at two opposite sides, for the extraction. A brewing fluid—generally hot water—is introduced at the first side. The brewed product is discharged from the capsule at the second side. Thereby, a considerable pressure for example of 5-20 bar must prevail in the inside of the capsule, depending on the drink to be prepared and the system.
In particular, aluminium and plastics, for example polypropylene have become known as capsule materials. Aluminium capsules provide a very good durability (aroma protection) of the extraction material but are very energy-costly in manufacture. Polypropylene capsules are advantageous with regard to the energy expense and disposal, but impose increased demands on the piercing mechanism and the aroma protection.
Capsules with integrated filter means as well as capsules that merely comprise an envelope enclosing the extraction material are obtainable on the market, and the piercing mechanism must thus be designed for these such that extraction material is not undesirably discharged from the capsule together with the extraction product.
A coffee portion capsule, which approximately has a cube shape, and, in contrast to the known beaker-like capsules, has no peripheral collar on the plane of the one (upper-side) cover surface is known from WO 2010/118543. Such a peripheral collar is required with capsule systems according to the state of the art, firstly in order to guide the capsule on insertion into the coffee machine and to hold it in an intermediate position after the insertion. Secondly, such a collar is necessary for closing the capsule by way of ultrasound welding or thermal sealing by way of a flat lid (which can also be designed as a foil). The collar is required on closure by way of ultrasound welding, in order to accommodate an energy director. If the capsule is closed by way of thermal sealing, the collar is necessary so that the lid rests on a sufficiently large surface. In contrast to this, an arched lid is used according to WO 2010/118543, and the closure is effected by way of ultrasound cut‘n’seal. The capsule manufactured according to the teaching of WO 2010/118543 accordingly, independently of its (“cube”) shape, instead of a collar has a welding bead which is peripheral between the planes defined by the cover surface, and whose extension/lateral projection is significantly reduced in comparison to known collars and represents an only insignificant departure from the corporal—for example cube-like—shape of the capsule.
Moreover, devices for discharging a brewed product from a portion capsule as well as for introducing a brewing fluid into a portion capsule are known from WO 2010/118544. These devices comprise perforation elements that project away from a support surface. The injection or discharge is effected past these perforation elements, and not through the perforation elements. Moreover, retaining webs can be assigned to the perforation elements, and these webs do not have a cutting edge preventing a bearing of a wall of the capsule on the support surface in an environment of the retaining web by way of the wall of the capsule bearing on the corner.
For a qualitatively good brewed drink, it is often important for the extraction material to be compact during the brewing process and not to swirl. The problem of the extraction material in the capsule not being able to be infinitely compacted, however, also exists due to reasons of manufacturing technology and/or due to a predefined capsule dimensioning and filling quantity.
It is suggested in WO 2008/015642 to compress the extraction material into a tablet in a capsule on filling and to subsequently close the capsule under vacuum conditions, so that the capsule lid after the closure is pressed onto the surface of the capsule and sticks there. The disadvantage with this solution is the fact that the extraction material can loosen again during transport and the tablet has no stability in the inside of the capsule, despite the vacuum prevailing in the capsule interior.
A system is moreover known from WO 2010/118545, with which the capsule is compressed during the brewing procedure by way of laterally engaging pressing bolts. This solution which, per se, functions quite well however has the disadvantages that it requires additional mechanical parts, and that the bolts engaging from the outside into the brewing chamber are difficult to accommodate for geometric reasons, depending on the design of the brewing chamber.